when, e.g., an injection mold is to be locked by using a pressing device, after a mold weighing, e.g., 100 kg is moved for 5 cm to a locking position, the mold is moved for only 1 mm to perform necessary mold locking. In mold locking, a pressure of 5,000 kgf is required to move a 100-kg mold for a travel of 1 mm. Although a kinetic energy of 100 kgf is sufficient for moving the 100-kg mold for 1 mm for initial positioning, 5,000 kgf is required to move this mold for the same distance of 1 mm for mold locking. Thus, if only one power source is provided, a kinetic energy of 5,000 kgf is required to move the mold for 5 cm as well. In this case, movement of 5 cm must be performed quickly, while mold locking of 1 mm must be performed slowly. Hence, a unit for changing the moving speed between movement and mold locking is also necessary. In a conventional pressing device, a lever unit is used to transmit a kinetic force from a power source to a press head, a force from the power source is applied to the force point of this lever unit, and the press head is connected to the action point. However, since an unnecessarily large power source must be used, the energy is wasted, and the apparatus becomes large in size.